<!DOCument html>
<html lang="zh_CN">
<head>
<style>
.div{width:500px; height:400px;border:1px red solid;margin:0 auto;}
</style>
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
$('p#n1').hide();
$('p#n2').hide();
$("button.a1").click(function(){
$('p#n1').hide();
$('p#n2').hide();
$('p#n3').show();
});
$("button.a2").click(function(){
$('p#n1').show();
$('p#n2').hide();
$('p#n3').hide();
});
$("button.a3").click(function(){
$('p#n1').hide();
$('p#n2').show();
$('p#n3').hide();
});

});
</script>
</head>
<body>
<div class="div">
<p id="n1"><img src="2.jpg" width="499px;" height="400px"></p>
<p id="n2"><img src="3.jpg" width="499px;" height="400px;"></p>
<p id="n3"><img src="1.jpg" width="499px;" height="400px;"></p>
</div>
<button class="a1">第一张</button>
<button class="a2">第二张</button>
<button class="a3">第三张</button>
</body>
</html>